A portable terminal device such as a cellular phone has a light source that emits light of various colors or patterns for the purpose of notifying the user of incoming communications. Such a light source is attached on a circuit board placed inside a housing, together with other electronic components.
A specific example of attachment of a light source in a portable terminal device is illustrated in FIG. 5. FIG. 5 is a sectional view of the vicinity of a light source in a portable terminal device. As illustrated in FIG. 5, a circuit board 302 is disposed inside a housing so as to face a front panel 301 that covers the front of the housing. On a facing surface 303 of the circuit board 302 that faces the front panel 301, an LED (Light Emitting Diode) 304 that serves as a light source is mounted. On the facing surface 303 of the circuit board 302, in addition to the LED 304, a receiver 305 is mounted that emits the other party's voice. The LED 304 is smaller in thickness than the receiver 305. Under such a configuration, light emitted from the LED 304 is projected onto the front panel 301 and released outside the device. As a result, the user may be notified of an incoming call.
In a camera-equipped portable terminal device, an LED and a camera are connected by a flexible substrate and mounted on a circuit board in order to enable photographing in a dark place as proposed, for example, in Japanese laid-open Patent Publication No. 2004-215223.
However, when a light source is mounted on a circuit board together with another electronic component and the electronic component is relatively large in thickness, the electronic component prevents the reduction in thickness of the device. That is to say, in the example illustrated in FIG. 5, when the receiver 305 placed between the front panel 301 and the circuit board 302 is relatively large in thickness, the distance between the front panel 301 and the circuit board 302 may not be set smaller than the thickness of the receiver 305. As a result, the receiver 305 makes it difficult to reduce the thickness of the device.
In the above case, a light source that is smaller in thickness than another electronic component is disposed on the same circuit board as the electronic component, and therefore light emitted from the light source may not be efficiently released outside the device. That is to say, in the example illustrated in FIG. 5, the LED 304 is smaller in thickness than the receiver 305. For this reason, the distance between the LED 304 mounted on the same circuit board 302 as the receiver 305 and the front panel 301 is limited by the thickness of the receiver 305, and it is difficult to place the LED 304 smaller in thickness than the receiver 305 close to the front panel 301. As a result, light emitted from the LED 304 is difficult to project onto the front panel 301 and to release outside the device.